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MELSEC-Q
6 DEDICATED INSTRUCTIONS
POINT
(1) The receive data storage device (D1) requires a contiguous free area equal to
or greater than the receive data length ((S) + 9) (maximum of 480 words).
(2) Execute the RECV instruction every time the corresponding channel's bit in the
RECV instruction execution request area (address: 205) of the buffer memory
turns on (there is receive data).
(3) When multiple Ethernet modules with the same network No. are installed to a
receive station, specify the "Un" to indicate which one is the target of the RECV
instruction.
When the "Jn" is specified in the RECV instruction, the PLC CPU will execute
the instruction to the module with the smallest starting I/O No..
(Example) To execute the RECV instruction at station No.3 for the SEND
instruction from station No.1, specify the "Un" as "U2".
(Send station)
SEND
CPU
Ethernet
module
CPU
Network No.1
(Receive station)
Station
No.2
Station
No.3
RECV U2
Station
No.1
Ethernet
module
Ethernet
module
1 The "Set by" column indicates the following:
• User: Data is set by the user before executing a dedicated instruction.
• System: The PLC CPU stores the execution result of a dedicated instruction.
2 For a list of error codes, see Section 11.3.3 of the Q Corresponding Ethernet
Interface Module User's Manual (Basic)
3 Nothing is stored if the execution source detects an error when receiving an
instruction.
Functions
(1) This instruction reads, via the Ethernet module of the local station, the data sent
from a station connected to an MELSECNET/H, MELSECNET/10 or Ethernet
network system, which is designated with the network number and station number
in the control data.
The data is sent using the SEND instruction.
When data is received from the send station, the receive data is stored in the
channel of the local station designated with the send station, and the
corresponding bit in the RECV instruction execution request area (address:
205) of the Ethernet module buffer memory turns on. The received data is read
from the receive data storage channel using the ON status of the corresponding
bit of the RECV instruction execution request area to time the reading
operations.
When reading the receive data from the Ethernet module is completed, the
completion device designated by (D2) turns on.
SEND
(D1)
[Local station]
[Response station]
QCPU
Ethernet module
RECV
Channel 1
Channel n
Channel 8
Ethernet
Q/QnACPU
Ethernet module
(D1)
(S)+2
Channel 1
Channel n
Channel 8
